Narrative:The aircraft departed Jenkinsburg on a skydiving flight. The engine lost power at approx 300 feet agl. and the Caravan then banked steeply left, spiralled in a steep nose down attitude and crashed. It appeared that the fuel in the tanks was contaminated with water and foreign material with the appearance of brown algae. A milky fluid (approx 65% jet fuel and 34% water) was found in the engine fuel control, as well as iron contaminants. Dark stringy material was found in the fuel filters. The aircraft had been refuelled from 55 gallon drums which contained contaminated fuel. The drums were stored upright and rain water could leak through the filler caps. N551CC had a history of fuel contamination which on occasions caused the fuel bypass indicator to display. Reportedly, the stall warning circuit breaker had been disengaged on other occasions, so as not to startle the jumpers; however, due to damage, its preimpact position could not be verified. The plane was estimated to be 370 lbs (168 kg) over its maximum weight limit and 1 inch forward of the CG limit.